ATACAMA

At September Faculty Meeting we proposed: A project of scientific excitement and uniqueness, in the IR niche; with focus that emphasizes Cornell’s instrument building talent; that can sensibly be completed in less than 10 yrs; that will place Cornell in the forefront of research in one of the most rapidly developing observational/ technological fields; that will provide Cornell with strong leverage for ALMA access/joint project development; of cost that will allow Cornell to lead. A development strategy that will place Cornell to advantage on a pathway to a “high altitude observatory”.

The first step: A 25m class FIR/submm telescope that will operate with high aperture efficiency down to 200  With large format bolometer array cameras (FOV>5’) and high res heterodyne receiver At a high site with PWV<1 mm and wide sky coverage NOT confusion-limited with exposures of 24 hrs or less

Science Highlights were discussed in: Primordial galaxies and early Universe evolution CMB and SZE science Heterodyne ISM science Star Formation/disks/planets environments Solar System science (KBOs) A Rough Estimate of Cost was provided: ~ $50M, including enclosure and one 1 st light major instrument (wide FOV bolometer camera)

Comparisons and Synergies were discussed with: 1.SIRTF: a cryo-cooled telescope of D=0.85m 2.Herschel: a cryo-cooled telescope of D=3.5m  both extremely sensitive but rapidly confusion limited in the FIR  both extremely sensitive but rapidly confusion limited in the FIR  will stimulate, rather than quench, research with the AT  will stimulate, rather than quench, research with the AT 3. JCMT: 15 m, submm telescope atop MK 4. CSO: 10m, submm telescope atop MK  currently best submm telescopes on Earth, confusion limited at  currently best submm telescopes on Earth, confusion limited at flux limits of cosmological (and other) interest flux limits of cosmological (and other) interest  show impact that unique submm facility can have (SCUBA)  show impact that unique submm facility can have (SCUBA) 5. APEX (Alma Precursor Experiment) 12 m telescope at Chajnantor  will likely be most sensitive submm telescope until ALMA starts ops.  will likely be most sensitive submm telescope until ALMA starts ops. at lower site and ¼ the collecting area, it will be overwhelmed at lower site and ¼ the collecting area, it will be overwhelmed by AT by AT 6. LMT: 50m, mm telescope atop Sierra Negra  very sensitive, but rapidly confusion-limited  very sensitive, but rapidly confusion-limited will excel in high resolution, interstellar gas spectroscopy will excel in high resolution, interstellar gas spectroscopy  poor site and antenna design prevents submm work  poor site and antenna design prevents submm work 7. ALMA: 64x12m array to operate ~ above 0.5 mm at Chajnantor  hi res, small FOV, eminently complementary with AT  hi res, small FOV, eminently complementary with AT

Comparative Sensitivities SIRTF Herschel APEX ALMA JCMT LMT AT

Events since the September Faculty Meeting: Several telecons with Caltech Joe V. meets with Head of Ast/Math/Phys Division of Caltech, Thomas Tombrello on Oct 9 Workshop in Pasadena on October 11 (BB, RG, TH and GS attend from Cornell) Agreement to jointly advocate for a Caltech/Cornell MOU Report of workshop, with MOU proposal, being drafted Improved cost estimate of project, using more elaborate set of scaling laws (BB)

What the Caltech/Cornell Report will contain: Review of science/technical/site highlights Recommendation that Caltech and Cornell sign an MOU and enter a Study Phase Recommendation that process take place in fast track mode emphasizing desirability of AT to be completed at same time as ALMA Recommendations for areas that will require priority attention in a Study Phase, from Science (precise definition of “discovery space”) Telescope (drop-dead surface quality level, design, wind, thermal, pointing, enclosure issues) Instrumentation (predict as accurately as possible development of fast-moving technology in next decade, define 1 st light) Site (verify asap PWV at Negro; obtain statistics for 200 mu A set of Working Groups formed to attend to those issues A proposed budget and duration for the Study Phase A draft of the MOU The report is to be presented to Joe and Tom T. within 2 weeks